Electric heating appliance



Apr. 17, 1923. 1,451,880

E. N. LlGHTFooT ELECTRIC HEATING APPLIANCE Filed Feb. 28 1921 2 Sheets-Sheet l 1 fsm Apr. 17, 1923.

E. N LIGHTFOOT ELECTRIC HEATING APPLIANGE Filed Feb. 28 1921 2 Sheets-Sheet 2 Patented Apr. .17, i923.

. UNITED STATES PATENT OFFICE.

EDWIN N. LIGHTFOOT, OF NEW YORK, N. Y., LASSIGNOR TO THE CUTLER-HAMMER MFG. CO., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

ELECTRIC HEATING APPLIANCE.

Application filed February 28, 1921. Serial No. 448,501.

T o alli/whom it may Concern Be it known that I, EDWIN N... Licirrroo'r,

a citizen of the United States, residing at New York, in the county ot Bronx and State of New York, vhave invented new and useful Improvements in Electric-Heating Appliances, of which the following is a specification. y

This invention relates to an electric heating appliance.

The electric heating appliance to which this invention particularly applies cornprises, in general, an elongated electric heater arranged within a casing and embedded in metal contained therein.

An object of this invention is to provide an eflicient and durable electric heating appliance, capable of being worked at high temperatures in the presence of acids wit out undue corrosion therefrom and having the following advantages:

It ma be readily and economically manufactured l It is thoroughly protected, resulting in lon life.

'I e electric heater may be readily removed rin the appliance.

Other objects and advantages will hereinafter appear. n

The views of the drawings are:

Fig l is a central longitudinal section through an electric soldering iron having the electricheater arranged in a single helix.

Fig. 2 is a transverse section on line 2-2 of Fig. 1. 4 r n Fig. 3 is a central longitudinal section through` an electric soldering iron having the electric heater 'arranged in a double helix.

Fig. 4 is a transverse section on line 4-4 of'Fig. 3.

Fig. 5 is a central vertical section through an electric can capping iron.

Fig. 6 is a transverse section on line 6 6 of Fig. 5.

Fig. 7 is a section through an electric heating appliance adapted for insertion in the wall of a container to be heated.

Fig. 8 is a central vertical section through an electric Crucible or vat provided with an integral pocket for receiving the cast-in electric heater.

Fi 9 is a central vertical section through an e ectric Crucible or vat provided with a removable pocket 'for receiving the cast-in electric heater.

Fig. 10 is a section through a portable immersion electric heating appliance.

Fig. 11 is a central vertical section through an electric branding iron.

Fig. 12 is ai bottom 4plan of the electric branding iron.

Figs. 1 and 2 will first be described.

The electric soldering iron comprises a shell or ca sing 1 containing an elongated electric heater 2, embedded in a metal core 3 filling the casing.

The sliell'or casing 1 is open at one end and is provided at the other with a threaded shank 4 for receiving a removable soldering tip 5.

The shell. or casing is made of non-corrodible and rust-resisting'material having a high melting point. Monel metal having these properties has been found to be satisiaactory.

The electric heater 2 may be of the type disclosed in Lightfoot-a'tent 1,359,400 of November 16, .1920. 'This electric heater has an elongated tubular jacket having a helical resistor 6 arranged therein and insulated therefrom by compacted granular' insulation and lug terminals 8 rigidly fastened to the jac et and connected to the resistor.

The electric heater 2 may be bent into any desired form. It is here formed into a single helix, one end of the heater passing through the helix, solas to arrange both terminals 8 at yone end'of the helix and beyond and near the open end of the casing 1.

The electric heater 2 is embedded in metal core 3 which fills the casing 1 and is held thereby in spaced relation to the casing. The heater jacket should be of metal having a higher melting pointthan that of the metal core in which it is embedded, so as to prevent melting the jacket when 'thai/'same is surrounded by molten core metal.

The core 3 is made of good heat conducting material such, for example, as brass, bronze, copper, aluminum, or type metal.

Thus, for soldering irons or other electric heating appliances working at high temperatures, a copper core having a relatively high meltingpoint may be employed.

An aluminum core may be used when the heating appliance is to be worked at relatively low temperatures or what it is permissible .for the Core-metal to be in a molten or plastic Condition while theappliance is at or near working temperature.

Aluminum being of good heat conductivity and having a low melting point is highly satisfactory as it is easily and quickly melted by a simple blow torch. Consequently, if

. 'an electric heater of an appliance should be damaged, the core metal may be readily melted and the damaged heater replaced by another.

The open `end of the Casing 1 may be covered bya cap'9 secured to the Casing by p ins 10 or other means.

Theuse of the cap 9 reduces the oxidation and deterioration of the Core metal andprevents the escape thereof shouldV the Core metal melt at working temperatures of the appliance.. The Yelectric heating appliance may be assembled in several dlerent ways.

The electric heater 2, after being bent-into the desired lform, may be positioned in the casing 1 and molten Core metal poured into lthe""""casing. The core'metal is then allowed to cool and harden.

Or the electric heater arranged in the desired form may be positioned in a temporary mold of the proper shape and the Core metal poured therein.. After being allowed to cool, the core with the heater castor embedded therein may be inserted in the casing as'by forcingor driving the same therein,

o'r the casing may be shrunk on the core.

It is desirable that the core fit tightly in the casing so as to reduce the temperature' gradient from the heater jacket to the casing.l

The Cap 9 having openings for the heater is then placed on thecasing and fastened theretoff 'The' insulating bushings 11 may 'then be screwed onto the plug terminals.`

Thus there is provided an eicient anddurable electric heatingapplianca capable of being worked at high ,temperatures in the presence of" acids, in 'which appliance vare combined the high heat' Conducting qualities of .the coremetal and the non-Corrodible and rust-resisting qualities of the shell or casing therefor. The shell or casing, therefore, serves to protect the high heatconducting core metal against the destructive 'acids or vapors therefrom which would otherwise attack and damage the same.l

Aloe moved, handles 24 are ceive nuts 12 and washers by'which Connection may be made to the terminals.

The capV 9 is provided with a central opening through which extends a plunger 13 which holds' the can cap in place while the same is being soldered.

Fig. 7 shows a heating appliance arranged so as to be received within an opening in the wall of a Chamber to be heated.

yThe casing 1 of this heating appliance is internally threaded for receiving the threaded Core 3 in which` the heater is embedded.

The plug terminals I8 of the heater are provided with extensions 14 threaded thereon and carrying terminal screws 15 by which connections may be made thereto.,

An externally threaded collar or ring v16, shrunk or otherwise rigidly fastenedto the casing 1 provides means by which the heating appliance may be secured within, a threaded opening in the wall of the chamber to beheated. Thus the appliance is supported by the wall of the chamber.

Fig. 8 shows the heating appliances associated with a Crucible or vat 17 containing the liquid to be heated. y

The casing 1 of the heating appliance. is formeel integrally therewith and extending into the same.

Fig. 9 showsa Crucible or vat equipped with a heating appliance which is removable therefrom. a y

The heating appliance is inserted through an opening in the bottom of the Crucible.

A flanged internally threaded ring 18,

registering with the opening, is rigidly fastened to the crucible by yrivets 19'or other means.

The casing 1 ofthe heating appliance is- Fig. 10 shows the heating appliance immersed'in a vat or Crucible. g The heating appliance may rest on the vbottom 'of the Crucible, while a hook 20 fastened tothe casing ot the appliance prevents it from beingcompletely immersed in the liquid contained therein. Figs." 11 and 12 show an electric branding iron having a removable branding plate 21 Vheld rmlyagainst the bottom of the ycasing 1 by screws 22 passing through lugs or projections 23 on the casing.

Other means may, of course, be used for fastening the branding plate to the Casing.

. In order that the branding iron may easily provided on the casing.'

The invention Claimed is: i v g1. -An electric heating appliance having,

in combination, a non-corrodible, rust-resisting casing, a high; heat-conducting metal AcoreJ within the casing. and an electric heater heat-conducting metal in contact with and surrounding the heater jacket and surfaced with substantially non-corrodble metal having a high melting point. v

4. An electric heating appliance comprising an electric heater having a tubular jacket enclosing an insulated resistor, high heat-conducting metal withinwhich the electric heater is embedded, and a Monel metal casin for the embedded electric heater.

5. i n electric heating appliance having,

yin combination, an electric heater provided with a tubular metal jacket enclosing an insulated resistor, lower melting point core metal in which the electric heater is embedded, and a substantially non-corrosive casing tightly embracing the embedded electric heater.

6. An electric heating a-ppliance comprising a cup-shaped substantially non-corrodible casing, a high heat-conducting metalcore within the casing, and an electric heater having a tubular metal jacket enclosing an insulated resstor and embedded in the core and projecting from the open end ofthe cas,-

g. An electric heating appliance `comprising a cup-shaped substantlallv non-corredible casing, a high heat-conducting metal core a within the casing, an electric heater having a tubular metal jacket enclosing an .insulated resistorand embedded in the core and projecting'from the/open end of the casing, and term' als for/file heating appliance rigidly faste 4ed to the heater jacket.

8. An electric heating appliancecomprising a cup-shaped substantlally non-corredible casing, a high heat-conducting metal core within the casing,a cover forl the open end ofithe casing, and an electric heater having aT tubular metal jacket enclosing an insulated resistor and embedded in the-.core

j and projecting through the cover.

9. An electric. heatingappliance comprising a cup-shaped substantially non-corrodible casing, a high heat-conducting metal core within the casing, a cover for the open end of the casing, an electric heater having a tubular metal jacket enclosing an insulated resistor and embeddedfin the core and projecting through the cover, and terminals for theheating appliance rigidly fastened to the heater jacket. 10. An electric heating appliance comprising a cup-shaped substantially non-corrodible casing, a high heat-conducting metal core within the casing, and an electric heater having a tubular metal jacket enclosing an insulated resistor and embedded in the core and projecting from the open end of the casing, the heater jacket having a higher melting point than the metal core.

11. An electric heating appliancevcompr'sing a cup-shaped high melting point substantially non-corrodible metal casing,

and an electric heater having a, tubular metal jacket enclosing an insulated resistor and Aarrangedin'the casing and embedded in high heat-conducting metal having a lower meltin point than the heater jacket. y

12. n electric heating appliance comprising a ycup-shapedhighI melting point substantially non-corrodible metal casing,

and an electric heater having a metal jacket `enclosing an insulated resistor and arranged in the casing and embedded in high heatconducting metal having a lower melting point than the heater jacket, a cap covering the open end of the casing and having the heater projectingtherethrough, and terminals for the heating appliance rigidly fastened to the heater jacket.

in combination a non-corrodible, rust-resistlng casing, a metal 'core within the casing, and an-electric heater embedded in the core and provided with an insulated resistor enclosed in a metal jacket whose melting point is higher than the core metal.

An electric heating appliance comprising an electric heater having a metal jacket enclosing an insulated resistor, and

Ametal cast around and about the heater jacket and surfaced with substantially noncorrodible metaltthe cast metal havin a lower melting pont than the heater jac et and the surfacing metal.

15.v An electric heating appliance com-` prisinga cup-shaped metal cam'ng, an electric heater having an insulated resistor arranged within an enclosing metal jacket, .and metal h avlng a lower melting point than the heater jacket and the casing, lling the casing and surrounding the electric heater.

In witness whereof, I have hereunto subscribed my name.

EDWIN N. LIGHTFOOT.

13. An electric heating appliance having, 

